1. Field of the Invention
The present invention relates to a complex crystal which is suitable for use as a light-adjusting component of a light valve or a light-adjusting glass, and which is composed of cation of a fused compound having a nitrogen atom in its molecule and anion of iodine.
2. Description of the Related Art
Conventionally, a light-adjusting component has been used to disperse light-polarizing particles into a dispersion medium, and to make them orient by applying an electric field on the dispersion medium. Furthermore, the light-adjusting component has been used to randomize the light-polarizing particles to control optical properties (light-transmitting and light-screening performance) of the dispersion medium. It is proposed that a complex ion such as herapathite is used as light-polarizing particles. When the light-polarizing particles are used for a light-adjusting component, a dispersion medium containing the light-polarizing particles is filled into a gap between a pair of transparent electrodes attached to a pair of transparent substrates. The dispersion medium may be filled into a micro cell in order to improve optical properties or safety of the light-adjusting component.
The above-mentioned dispersion medium containing the light-polarizing particles almost contains moisture. Therefore, molecules of water destroy a clathlate structure of a complex ion. As s result, polarizability deteriorates. The light-polarizing particles which are known at present have poor moisture resisting property. In order to obtain durability and stability of a light-adjusting component, light-polarizing particles require excellent moisture resisting property.
Since automobiles have been improved their performance, it is desired that a windshield glass can screen a light. Therefore, it is necessary to manufacture a light-screening glass as a light-adjusting component by using light-polarizing particles. When a light-screening glass is formed by a light-adjusting component comprising the above-described light-polarizing particles, a dispersion medium containing the light-polarizing particles should be sealed in the middle stage of manufacturing a laminated glass. However, the light-polarizing particles deteriorate or decompose when they are exposed to a temperature above 100.degree. C. Therefore, the light-polarizing particles are not suitable for use as the laminated glass for automobiles which is produced at a temperature above 130.degree. C.
In order to obtain a long-lived light-adjusting component, it is required to provide a complex crystal which shows excellent heat resistance and excellent moisture resisting property.